Dwarf Planets

When Pluto was first discovered, it was considered to be the 9th planet in our Solar System. But as telescopes grew more powerful astronomers discovered more objects that lie near Pluto and even rival its size. This was fuelled when Eris, a body that was bigger than Pluto, was discovered.

In 2006, after much discussion, Pluto was stripped of its status as a planet. The scientists agreed that for a celestial body to qualify as a planet: